The present invention is directed to an improvement in a mass soldering system of the type described in the earlier patents of H. T. O'Rourke, U.S. Pat. Nos. 4,410,126 and 4,401,253. This prior patented system involves directing a hot air knife blast onto the bottom surface of a printed component-carrying circuit board, the air blast impinging on the surface immediately after the printed circuit board leaves a wave soldering system. The impinging air blast is reported to reduce the incidence of solder shorts, icicling and/or bridging, and has achieved widespread adoption.
In working with the previously patented system of O'Rourke, it has been found that with certain types of components, different angles of air blast give optimum solder removal to prevent solder shorts, icicling and/or bridging.